React 中的状态没有更新

Question

我正在关注 YouTube 上关于 React 版本 16 中测验应用程序的教程。在状态和函数中有一些变量，这些变量在 setState 的帮助下更新。变量的值没有被更新。正在更新这些变量的函数中的以下内容。正在从 componentDidMount 函数调用此函数。

displayQusetions = (questions = this.state.questions, currentQuestion, nextQuestion, previousQustion) => {
   let { currentQuestionIndex } = this.state;
   if (!isEmpty(this.state.questions)) {
      questions = this.state.questions;
      currentQuestion = questions[currentQuestionIndex];
      nextQuestion = questions[currentQuestionIndex + 1];
      previousQustion = questions[currentQuestionIndex - 1];
      const answer = currentQuestion.answer;

      this.setState({
         currentQuestion,
         nextQuestion,
         previousQustion,
         answer
      })

      console.log(this.state.currentQuestion);
      console.log(this.state.nextQuestion);
      console.log(this.state.previousQustion);
      console.log(this.state.answer);
   }
}

我是新手。请帮忙。

Answer 1

您可以在回调

中查看状态更新值

this.setState({
                currentQuestion,
                nextQuestion,
                previousQustion,
                answer
            },()=>{
            console.log(this.state.currentQuestion);
            console.log(this.state.nextQuestion);
            console.log(this.state.previousQustion);
            console.log(this.state.answer);

})

React 中的状态没有更新

The state is not updating in React

javascript

setstate

reactjs